This invention relates to an arrangement for providing electrical connections to pin electronics cards in a test head.
When a conventional semiconductor integrated circuit tester is used in conjunction with a wafer prober, the test head of the tester is typically placed directly above the wafer prober for sequentially testing wafers that are delivered to the test head from below. The test head houses pin electronics on rectangular pin electronics cards, and the pin electronics cards are disposed so that each card lies in a vertical plane and the edges of the cards are vertical and horizontal. Each card has terminals distributed along its lower edge and these terminals are connected to a probe card through a device interface board. When a wafer is positioned for testing, the wafer prober lifts the wafer and contact pads on the upper surface of the wafer engage probe needles that project downwards from the probe card.
For compactness, the pin electronics cards may be positioned in two rows. The cards are arranged in pairs, one card of the pair in each row.
The pin electronics cards are electrically connected at their upper edges to a backplane structure including conductors that provide electrical operating power and test data to the pin electronics circuits. The connections between the pin electronics cards and the backplane structure should be releasable in order to facilitate replacement of a defective pin electronics card or upgrade of a pin electronics card.
Since the backplane structure is normally rigid, in order to engage or disengage a connection between a pin electronics card and the backplane structure it is necessary that the connections between all the pin electronics cards and the backplane structure be engaged and disengaged simultaneously. A tester might have several thousand pin electronics circuits. Therefore, it can be difficult to supply the force that is necessary for simultaneous engagement or disengagement of the pin electronics cards.